Scientists discover why astronauts struggle to poop in space

Astronauts can face an awkward but important problem in space when their digestive systems slow down, making it harder to pass stool normally. A new study published in Nature Communications has now found biological clues that help explain what may be happening inside the gut during spaceflight. Researchers analysed blood samples from astronauts who spent between two and nine months aboard the International Space Station, looking at changes in hundreds of small molecules produced by the body, food and gut microbes. The results point towards slower movement of intestines in microgravity. When material stays in the gut for longer, microbes appear to rely more heavily on protein rather than fibre and carbohydrates for energy.